Docetaxel is an anti-cancer agent effective in treating non-small cell lung, breast, ovarian, head and cervical cancers. It is commercially available under Taxotere® by Sanofi-Aventis. Docetaxel is a highly lipophilic semisynthetic taxoid but is almost insoluble in water. Docetaxel is currently distributed in a blister carton package consisting of one single-dose Taxotere containing docetaxel dissolved in polysorbate 80 vial and one single-dose solvent for Taxotere containing 13% (w/w) ethanol vial, wherein the above two are mixed together to prepare a premix with a solubility of 10 mg/mL and then added into an infusion bag containing physiological saline solution. The final infusion solution should have a docetaxel concentration ranging from 0.3 to 0.9 mg/mL. If the concentration is higher than 0.9 mg/mL, there may appear precipitation. In addition, hypersensitive reaction may occur due to the use of polysorbate 80 and the presence of ethanol may incur side reactions.
WO 98/30205 discloses a method of using PEGylated vitamin E as a surfactant and US 2004/0127551 discloses a method of using vitamin E TPGS (D-α-tocopheryl polyethylene glycol 1000 succinate). But, they failed to obtain a stable composition containing a high concentration of docetaxel.
Korean Patent No. 310839 discloses a method of preparing a polyvinylpyrrolidone matrix and mixing it with anhydrous ethanol and a solvent such as polyoxyethylene glycerol ricinoleate, polysorbate 80, anhydrous ethanol and polyethylene glycol to obtain an injection. However, the above invention is also not advantageous in that the substances that may induce alcoholism or hypersensitive reaction (ethanol and polysorbate 80) are included.
WO 99/24073 filed in 1997 discloses a method to increase the solubility of docetaxel in water by using cyclodextrin instead of a surfactant. More particularly, docetaxel is dissolved in a small amount of ethanol and the resultant solution is added to a 5% dextrose solution of acetyl-γ-cyclodextrin (Ac-γ-CD) or hydroxypropylmethyl-β-cyclodextrin (HP-β-CD). Then, ethanol is removed as much as possible by evaporation or other method as appropriate. Subsequently, lyophilization is performed to obtain a wanted lyophilized composition. A suitable mixed ratio of docetaxel to cyclodextrin is from 1:25 to 1:400 based on weight. An injection obtained by further diluting the resultant lyophilized composition in a 5% dextrose solution has a concentration of 0.3-1.2 mg/mL and enables to maintain physical stability for over 72 hours.
However, this invention also has the problem that the ethanol used to dissolve docetaxel may not be eliminated, and precipitation may occur if the resultant liquid composition has a low docetaxel concentration. Further, since lyophilization is performed after adjusting the docetaxel concentration of the liquid composition to 0.5-1.25 mg/mL, the dried substance has a large volume, leading to a smaller throughput for a single batch of the same lyophilizer. Besides, when the resultant lyophilized composition is dissolved or diluted for use, its physical stability tends to decrease and the resultant lyophilized composition does not have the solubility 10 mg/mL, which is the solubility of the Taxotere's pre-mix solution. In case an injection for clinical administration is prepared as disclosed in the patent by dissolving it to a docetaxel concentration of 0.5-1.25 mg/mL using 5% dextrose or 0.9% saline solution, about 150-200 mg of the substance should be used considering the clinical dose of 100 mg/m2. Consequently, about 150-200 mL of diluent is required and it is very difficult to prepare the required injection.
Accordingly, there is still a need for the development of a new pharmaceutical preparation that can offer improved storage stability and solubility as compared to those of conventional formulation and does not require a harmful solubilizing agent such as polysorbate or ethanol.